Study On The Drug Delivery System On The Surface Of Polyether Ether Ketone Bionic Bone

At present,the orthopedic disease patients have reached up to 10 millions in China.Diseases related to bone system have posed a serious threat to national health.Therefore,the study of bone materials is of great significance to the development of national health.In this paper,PEEK porous scaffolds with different porosity were prepared and tested for their mechanical properties.It was found that the compressive yield strength and compressive modulus of porous materials decreased with the increase of porosity.When the pore size distributions were mainly between 150 μm and 450 μm with porosity of 72.38 %,the compressive yield strength was 2.82 MPa,and the compressive modulus was 68.19 MPa.But the compressive yield strength was 0.56 MPa,and the compressive modulus was 26.56 MPa with porosity of 86.89 %.When the pore size distributions were mainly between 100 μm and 250 μm with porosity of 71.9 %,the compressive yield strength was 2.41 MPa,and the compressive modulus was 60.86 MPa.But the compressive yield strength was 0.44 MPa,and the compressive modulus was 24.2 MPa with porosity of 85.6 %.The PEEK porous materials with different thickness ratios of porous layer and compact layer were prepared,and its mechanical properties were tested.It was found that with the increase of the thickness ratio of the porous layer,the mechanical properties showed a decreasing trend,and the mechanical properties of the porous layer with larger porosity decreased more obviously.The drug-loaded PLGA microspheres were prepared by emulsion emulsification method.The encapsulation efficiency,drug loading rate and particle size distribution of PLGA microspheres were measured.It was found that with the increase of PLGA concentration from 10 mg/m L to 40 mg/m L,the rate of encapsulation increased gradually from 42.43 % to 50.85 %.And the drug loading rate increased firstly and then descended,followed by 1.82 %,2.15 %,2.41 %,and 2.22 %.With the increase of PLGA concentration the particle size distribution of the microspheres increased,and the volume average size of microspheres was 4.73 μm,5.84 μm,13.28 μm,17.44 μm.The PEEK porous scaffolds were subjected to osteoconduction performance test.The proliferation,alkaline phosphatase(ALP)activity and gene expression of osteoblasts were detected.It was found that with the increase of incubation time,a large number of cells were present on the scaffold surface after 14 days.The bone scaffold with rougher surface and higher porosity lived more cells,and genetic expressions of RUNX2 and COL1 A were more.The ALP activity of bone scaffolds with higher porosity and smaller hole was higher.And the ALP activity of bone scaffold without hole was lowest.The SEM images showed that the cells were more likely to stick to the rough surface of the hole.And the surface through the sandpaper polished place where there were many pore channel with the size of 10 μm had some adherent cells.